Water cooling system for marine motors



Aug 18, 1931.. RGENs 1,818,991

' WATER COOLING SYSTEM FOR MARINE MOTORS Filed Jan. 8, 1927 I N VEN TOR O BY ENNTIRcENs A TTORNEY5 Patented Aug. 18, 1931 UNITED STATES BAT ENT OFFICE FINN T. IRGENS, OF JACKSON, MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

OUTBOARD MOTORS CORPORATION, OF

MICHIGAN i DETROIT, MICHIGAll', A CORPORATION OF WATER COOLING SYSTEM FOR MARINE MOTORS Application filed January 8, 1927. Serial No. 159,779.

' My invention aims to provide a water cooling system for marine motors or power plants adapted for driving a submerged propeller, and the propeller is utilized to provide a circulation of water in connection with the motor or power plant for cooling purposes.

A conventional type of marine motor, includes and adjustable bracket supported col-. umn adapted for attachment to the stern of a boat with the motor located at the upper end of the column and a rudder, gear housing, and propeller located at the lower end of the column; In the column and gear housing is a power transmission mechanism by which'the motor may drive the propeller. It is in con-. nection with this type of marine'motor that I cause a circulation of water, for motorcooling purposes, by a novel construction in on nection with the propeller, gear housing, and rudder. The circulation is induced by a suction produced by the centrifugal action of the propeller; by the ejector action of water being discharged, and by a scooping or intake action by which water has .a forced circulation.

The construction entering into my invention, together with certain advantages gained thereby, will be hereinafter described .and then claimed, and reference will now behad to the drawings, wherein Figure 1 is a side elevation of a conventional form of marine motor reconstructed in accordance with this invention;

Fig. 2 is an enlarged end view of the propeller;

Fig. 3 is an enlarged longitudinal sectional View of the propeller, and adjacent parts, and

Figs. 4-, b and 6 are cross sections of propeller blades showing act-ions which may be obtained for a motor cooling system.

in the drawings, 1 denotes a boat clamping bracket and operatively connected thereto is a tubular column 2 supporting a conventional form of marine motor 3 at its upper end.

Suitably supported from the lower end of the column 2 is a gear housing t having an upper rudder member and a lower rudder member 6, both of which serve somewhat as a guard for a bladed propeller 7 supported from the gear housing 4. The propeller 7 is ordinarily fi xed on a driven shaft 8 suitably journaled in the gear housing 4 and adapted to be driven by suitable power transmission from the motor 3. Instead of using a conventional form of propeller and rudder assembly at the lower end of the column 2, I have redesigned these elements to include the followmg novel construction.

I The upper rudder member 5 is formed with two chambers, channels or the like designated 9 and 10. The chamber 9 is in the front edge of the rudder member 5 and said chamber has its lower end open and of such configuration that it will constitute an easy entry for water into the chamber. The arrangement and configuration of the chamber 9 are such that it will havea scooping eifect for the intake of water so that as the rudder member is moved through'a body of water there will be a forcible intake of the water, which flows through the chamber 9 into a conduit 11 connecting the ruddermembertowater jacket 3 of the marine motor. There is a return conduit 12 from the water jacket to the upper end of the chamber formed in the rear part of the rudder member'5. The conduits l1 and 12 are shown, as a matter of convenience outside of the column 2, but in some instances the conduits or water passages may be within the column, so I prefer to consider the conduits as a means of conducting water to and from the marine motor. v

The lower end of the rudder chamber 10 is reduced within the gear housing 4 and is formed around the driven shaft 8 to communicate with a bore or passage 13 in the rear end of the driven shaft 8. Permanent communication is established by an opening 14 in the wall of the bore so that water may readily enter the rear end of the shaft 8 and pass out of an opening 15in the wall of the bore into a propeller chamber 16 formed in the hub portion of the pro eller.

The propeller has its blades 17 provided with curved passages 18 opening at the back side of the propeller adjacent the trailing edge of each blade, as best shown in Figs. 2 and 3, and as a result of these blade passages water may be forcibly discharged by the centrifugal action of the driven propeller. AB

the propeller blades cut the water a suction is produced at the open outer ends of the passages 18 and this suction, together with the centrifugal action of the propeller produces a positive discharge of water so that an eiector action is set up throughout the circu ating system that insures a rapid movement of water in the system for cooling purposes. lVith all of these suction actions cooperating with that of the forced intake at the chamber 9 it is only a matter of dimensions to obtain a sufficient volume of water for motor cooling purposes.

In Fig. 4 the blade 17 has its passage 18 exhausting on the convex face 19 of the blade and the cutting action of this blade relative to a body of water is indicated by-water flow lines with the action being that of an ejector when the propeller and lines of water flow are in the drawings indicated by arrows.

To provide a suction or partial vacuum action the passage 18 may have its exhaust curved towards the convex face of the blade, as indicated at 20 in Fig. 5. In the operation of this propeller blade the convex face 19 produces a suction action with the opposite face of the blade for driving purposes. Somewhat of a similar result maybe attained by providing the blade 17 with a trailing edge 21 for a straight exhaust of the passage 18. This is shown in Fig. 6 and'the suction produced at the trailing edge of said blade will readily cooperate with the centrifugal action of the propeller and the forced intake of water in maintaining a circulation for motor cooling purposes.

As a matter of good construction the chamber 16 and its outlet passages 18 have been embodied in the propeller, but the same results could be attained if a structure affording such chamber and passages were attached to an ordinary propeller.

From the foregoing it will be observed that I have devised a method of cooling a boat power plant, as an outboard motor, the method consisting in scooping water to cause it to flow towards the power plant, and then utilizing the centrifugal action of a water discharging propeller for producing a suction by which a circulation of water is maintained through the power plant and out of the propeller.

On account of some outboard motors having separate rudders, I desire the term.rudder structure to be interpreted as including any under water structure.

struction other than what may be hereinafter definitely claimed.

What I claim is :-f

1. IIL an outboard motor, a power plant, a chambered rudder structure adapted to receive and discharge water, said structure having a chamber formed in the leading edge thereof, a conduit extending from said chamber tosaid power plant and adapted to conduct water thereto, a discharge conduit extending from said power plant to said rudder structure and adapted to carry water from said power plant, a propeller shaft journalled in said rudder structure, a propeller mounted on said shaft and having passages formed longitudinally in the blades of said propeller, said passages being open at their outer ends, and means of communication between said second named conduit and the inner ends of said passages substantially closed against the admission of water to said pasa'ges from sources other than said discharge conduit, whereby the suction developed in said passages will circulate water through said conduits.

2. In an outboard motor, a power plant, a

chambered rudder structure, adapted to receive and discharge water, said structure having a chamber formed in'the leading edge thereof, a conduit extending from said chamher to said power plant and adapted to conduct water thereto, a discharge conduit extending from said power plant to said rud der structure and adapted to carry water from said power plant, a bored propeller Tl shaft journalled in said-rudder structure and closed at its end, means of communication between said last named conduit and the interior of said propeller shaft, and a propeller mounted on said shaft and having passages formed longitudinally in the blades thereof, said passages having their outer ends open and their inner ends in communication with the interior of said shaft and therethrough solely with said discharge conduit.

In testimony whereof I afiix my signature.

FINN T. IRG'ENS.

Obviously there maybe various kinds of discharge connection of the motor or engine other than by conduits and the rudder structure, therefore I do not care to limit my in-' 'vention to any particular mechanical con- 

